Variable condenser



Jan. 12 1926. 1,569,211

E. w. SPENCER I VARIABLE CONDENSER Filed May 16, 1924 Stem-M a variable plate condenser ior ra Patented Jan. 12, 1926.

ELMER VI. SPENCER, OF HEMLLE, MISSOURI.

VARIABLE CONDENSER.

Application filed T0 aZZ whom it may concern Be it known that I, ELMER \V. SPENCER, a citizen of the United States, residing at Hemple, in the county of Clinton and State of Missouri, have invented certain ne and useful Improvements in Variable Condensers, of which the following is a spcc ification.

This invention relates to variable condensers.

An object of this invention is to provide lio sets, wherein means is provided for mount 1g and adjusting the movable plates of said condenser, so that the same will slide in a longitudinal direction, in and out of rela tion between the stationary plates.

Another object of the invention resides in providing a variable plate condenser for radio sets, wherein a base member mounts the stationary plate of the condenser, and is provided with means for mounting movable condenser plates adapted for sliding movement relative to the stationary plate, for varying the capacity of the condenser, and for mounting an adjusting means adapted to effect the slid ng movement of the plate, having a rotatable knob provided with suitable means for transforming the rotary movement thereof, into a sliding movement of the plate.

he invention also includes other objects and improvements in the details of construction and arrangement of the parts, which are more particularly pointed out in the following description and claim, directed to a preferred form of the invention, it being understood, however, that various changes in the size, form, and structure of the device may be made, without departing from the spirit and scope of the invention as described and claimed.

In the drawing, forming part of this application:

Figure 1 is a side elevation of condenser.

Figure 2 is an end elevation thereof.

1 indicates a base, which is preferably formed of a fiber plate or like insulating material, and on which is mounted the stationary condenser plate indicated at 2 by any suitable means, such as a bolt and nut connection 8. A plurality of rods are mounted in spaced parallel relation with each other, and at the corners of the base 1., as igulic ited at it, and on which are slidable 192%, Serial NO- 713,760.

bearing sleeves 5, which receive and carry a removable plate 6, constructed of fiber or other insulating material, and which is similar to the plate 1, for mounting the movable condenser plate 7, for relative sliding adjustment, with respect to the stationmy plate 2.

A plate member is indicated at 8, having offset end portions 9, which are provided with openings at the corners for receiving the rods at, and which are secured to said rod by means of the cooperating nuts 10, threadably mounted on the end portions of rods 4. This forms a convenient means of mounting and retaining the rod l, in rigid spaced relation, and also a means of mount ing the condenser on the instrument panel of a radio receiving set or the like, for operation in connection with the radio cir cuit, the plate member being constructed of metal, which will absorb and prevent bodv inductance, in the condenser. v

A bracket member is indicated at 11, which is provided with a plurality of extensions 12, projecting laterally from one side of the plate 13 thereof, and formed with angularly bent end portions to provide securing feet 14, so that the bracket may be secured to the movable plate 6, slidable on the rod 4-. A member 15 is rigidly secured in the plate 13 of bracket 11, and is formed with a central screw threaded opening for receiving the threaded end portion of the operating shaft 16, which extends through an opening in the member 8, and is held against endwise movement with re spect thereto by a collar 17, rigidly mounted on the shaft, and retained against the bottom portion of the plate member 8, by U-shaped brackets 18, secured to said plate member 8. The end of the shaft projects substantially beyond the plate member 8, and is adapted to extend through the instrumentboard of a radio receiving set, and receive on the outer end thereof a knob 19 by which the shaft may be rotated, for adjusting the condenser.

From the foregoing description, it will be seen that when the condenser is properly connected in the radio circuit, the rotation of the knob 19 will effect a rotation of the shaft, and in View of the collar 17 holding the same against movement with respect to the plate .8, the threaded cooperation between the shaft and the member 15 will effeet a longitudinal movement of the men ber 15 on the shaft, for sliding the movable plate 6 on the rod 41-, and moving the movable condenser plate relative to the stationary plates for varying the capacity of the condenser.

It will therefore, be clear from the foregoing description that a novel and eilicient variable condenser has been provided, wherein the movable plates are adapted tor relative sliding movement with respect to the stationary plate, for varying the capaeity of the condenser, through the operation of the shaft 16, and by which it will readily be seen that exceedingly fine adjustment of the condenser for tuning purposes will be effected, so that the present construction of condenser enables the combination of a main and Vernier condenser in the one structure, the adjustment for the movable condenser plate effecting the Vernier adjusting action thereof.

That is claimed is:

A variable condenser comprising a base of rectangular form, a plurality of rods mounted at the corner portions of said base and extending laterally therefrom in spaced parallel relation, a plurality of parallel spaced condenser plates mounted on said base and extending therefrom in lateral relation, a movable plate having guides slidably titting said rods, a plurality oi. spaced parallel condenser plates mounted on said movable plate and projecting laterally therefrom adapted for movement in all of the relations and in spaced relation between the condenser plates mounted on said base member, a plate member removably mounted on the end portions of said rod, a shaft rotatae bly mounted in said plate member and held therein against axial movement, a U-shaped bracket member mounted on said. movable plate member, and a block member mounted in said U-shaped bracket member having a threaded opening threadedly cooperating with the threaded portion of said shaft for ell'ecting a sliding movement of the movable plate member on said rod on the rotative movement of said shaft.

In testimony whereof I affix my signature.

ELMER XV. SPENCER. 

